Question

The chemical formula of iron (iii) carbonate is:
A. $F{e_2}{\left( {C{O_3}} \right)_2}$
B. $F{e_2}\left( {C{O_3}} \right)$
C. $F{e_2}{\left( {C{O_3}} \right)_3}$
D. $Fe{\left( {C{O_3}} \right)_2}$

Answer 1

Hint: Every chemical compound has a fixed composition and number of atoms present in the compound. Chemical formula is a set of chemical symbols showing the elements present in a compound and their relative proportions.

Complete step by step answer:
A chemical formula tells us the number of atoms of each element in a compound. It contains symbols of the atoms of the elements present in the compound. Each chemical substance has a specific chemical composition.
Steps for writing a chemical formula:
(i) First, you have to decide the type of bonds either covalent bond or ionic bond.
(ii) Write the symbol of a polyatomic ion or the element.
(iii) Write the valency of each atom or group of atoms.
(iv) Now, after writing the valency of each atom or group of atoms, balance the charge of each species.
Given:
Chemical formula of iron (iii) carbonate is

Symbol of atomsOr group of atoms	$Fe$	$C{O_3}$
Charge	$ + 3$	$ - 2$

The chemical formula of iron (iii) carbonate is $F{e_2}{\left( {C{O_3}} \right)_2}$

Hence, the correct option is (C).

Note:
Monoatomic ions are composed of single atoms and polyatomic ions are composed of two or more atoms per ion.